Frequencies for first 10,000 rows of f_ol_prolong variable in natlterr2008 dataset :

  Prolonged |
      Labor |
(op_prol) R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,066       60.66       60.66
          1 |      3,934       39.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015